Quantitative phase Analisis: A comparative study of Mo and Cu strictly monochromatic radiations

A comparison of the Rietveld quantitative phase analyses (RQPA) obtained using Cu-Kα1, Mo-Kα1, and synchrotron strictly monochromatic radiations is presented. The main aim is to test a simple hypothesis: high energy Mo-radiation, combined with high resolution laboratory X-ray powder diffraction optics, could yield more accurate RQPA, for challenging samples, than well-established Cu-radiation procedure(s). In order to do so, three set of mixtures with increasing amounts of a given phase (spiking-method) were prepared and the corresponding RQPA results have been evaluated. Firstly, a series of crystalline inorganic phase mixtures with increasing amounts of an analyte was studied in order to determine if Mo-Kα1 methodology is as robust as the well-established Cu-Kα1 one. Secondly, a series of crystalline organic phase mixtures with increasing amounts of an organic compound was analyzed. This type of mixture can result in transparency problems in reflection and inhomogeneous loading in narrow capillaries for transmission studies. Finally, a third series with variable amorphous content was studied. Limit of detection in Cu-patterns, ~0.2 wt%, are slightly lower than those derived from Mo-patterns, ~0.3 wt%, for similar recording times and limit of quantification for a well crystallized inorganic phase using laboratory powder diffraction was established ~0.10 wt%. However, the accuracy was comprised as relative errors were ~100%. Contents higher than 1.0 wt% yielded analyses with relative errors lower than 20%. From the obtained results it is inferred that RQPA from Mo-Kα1 radiation have slightly better accuracies than those obtained from Cu-Kα1. This behavior has been established with the calibration graphics obtained through the spiking method and also from Kullback-Leibler distance statistic studies. We explain this outcome, in spite of the lower diffraction power for Mo-radiation (compared to Cu-radiation), due to the larger volume tested with Mo, also because higher energy minimize pattern systematic errors and the microabsorption effect.

The use of mo and cu monochromatic radiations for quantitative phase analysis: study of the accuracy

Cement hydration is a very complex process in which crystalline phases are dissolving in water and after supersaturation hydrated crystalline and amorphous phases precipitate. Great efforts are being made to develop analytical tools to accurately quantify these processes and X-ray Powder Diffraction (XRPD) combined with Rietveld methodology is a suitable tool to quantify these complex mixtures and their time evolutions. However, some problems/drawbacks should be overcome to fully apply it to cement pastes characterization in order to get accurate phase analyses. In order to tackle this issue, a comparison of the Rietveld quantitative phase analyses (RQPA) obtained using Cu-Kα1, Mo-Kα1, and synchrotron strictly monochromatic radiations of three set of mixtures with increasing amounts of a given phase (spiking-method) is presented. The main aim is to test a simple hypothesis: high energy Mo-radiation, combined with high resolution laboratory X-ray powder diffraction optics, could yield more accurate RQPA, for challenging samples, than well-established Cu-radiation procedure(s). Firstly, a series of crystalline inorganic phase mixtures with increasing amounts of an analyte was studied in order to determine if Mo-Kα1 methodology is as robust as the well-established Cu-Kα1 one. Secondly, a series of crystalline organic phase mixtures with increasing amounts of an organic compound was analyzed. This type of mixture can result in transparency problems in reflection and inhomogeneous loading in narrow capillaries for transmission studies. Finally, a third series with variable amorphous content was studied. Limit of detection in Cu-patterns, ~0.2 wt%, are slightly lower than those derived from Mo-patterns, ~0.3 wt%, for similar recording times and limit of quantification for a well crystallized inorganic phase using laboratory powder diffraction was established ~0.10 wt%. From the obtained results it is inferred that RQPA from Mo-Kα1 radiation have slightly better accuracies than those obtained from Cu-Kα1. The results obtained in the previous comparison have been taken into account to obtain accurate RQPA, including the amorphous component with internal standard methodology, of hydrating cement pastes. The final goal of this second study was understanding the early-stage hydration mechanisms of a variety of cementing systems (Ordinary Portland Cement or Belite Alite Ye’elimite cement) as a function of water content, superplasticizer additives and type and content of sulfate source. In order to do so, X-ray powder diffraction data were taken in-situ with the humidity chamber coupled to the Mo-Kα1 powder diffractometer. Some results of this ongoing investigation will be reported and discussed.

Lectura y escritura de palabras y pseudopalabras a los seis y siete años en niños españoles

El objetivo de este estudio es comparar a los seis y siete años la lectura y la escritura de palabras y pseudopalabras en sujetos españoles. La muestra está formada por 116 alumnos, inicialmente de seis años, pertenecientes a un nivel sociocultural medio, de habla castellana y sin necesidades educativas especiales. Los sujetos fueron evaluados a los seis y siete años en exactitud, velocidad y eficiencia lectora de palabras y pseudopalabras, así como en exactitud escrita de palabras y pesudopalabras. Tras la realización de análisis descriptivo-exploratorios y sendas pruebas t de Student para muestras relacionadas, los resultados indican diferencias significativas entre lectura de palabras y lectura de pseudopalabras (exactitud, velocidad y eficiencia) y entre escritura de palabras y escritura de pseudopalabras (exactitud) a los 6 y 7 años, siendo el rendimiento lector y escritor mayor con palabras que con pseudopalabras en ambas edades. También se encontraron a los 6 y 7 años diferencias estadísticamente significativas entre lectura y escritura de palabras (exactitud), así como entre en lectura y escritura de pseudopalabras (exactitud), siendo el rendimiento en lectura y escritura de palabras mejor que el de pseudopalabras en ambas edades. Se discuten los resultados encontrados en función de las características de las tareas y de las distintas formas de acceso al léxico.

Conocimiento fonológico, denominación rápida y memoria fonológica en sujetos españoles

El objetivo de este estudio es comprobar si existen diferencias en algunos predictores cognitivos de la lectura (conocimiento fonológico, denominación rápida alfanumérica y no alfanumérica, y memoria fonológica) entre los seis y a los siete años en sujetos españoles. La muestra está formada por 116 alumnos de seis años inicialmente, pertenecientes a colegios de nivel sociocultural medio, de habla castellana y sin necesidades educativas especiales. Los sujetos fueron evaluados a los seis y siete años en las competencias cognitivas del estudio. Tras la realización de análisis descriptivo-exploratorios y sendas pruebas t de Student para muestras relacionadas se encontraron diferencias estadísticamente significativas entre los 6 y los 7 años tanto en conocimiento fonológico como en nombramiento rápido alfanumérico y no alfanumérico, siendo mejor la ejecución a los 7 años. Sin embargo, las diferencias no fueron estadísticamente significativas en memoria fonológica entre los 6 y los 7 años. En función de estos resultados, cabe esperar que las relaciones de estas variables con la lectura y la escritura de palabras y pseudopalabras a estas edades sean diferentes. Se resalta la implicación de los resultados en la práctica educativa, con el fin de prevenir las dificultades de aprendizaje y optimizar los procesos de enseñanza-aprendizaje de la lengua escrita en español.

Exploring value creation with Social Media use in hotels

En la última década las tecnologías de Social Media han revolucionado el entorno competitivo, reinventando la forma de relacionarse con los clientes. En el sector hotelero, hoteles de todo el mundo están usando dichas herramientas para atraer a los clientes, estableciendo conversaciones colaborativas con ellos que vayan forjando vínculos emocionales con la marca. Asimismo, los hoteles se han dado cuenta de que herramientas Social Media se han convertido en facilitadoras de estrategias CRM (Gestión de Relaciones con Clientes), por lo que están integrando el uso de ambas herramientas para conocer mejor a sus clientes. No obstante, a pesar de la gran relevancia y del uso generalizado de Social CRM, la eficacia de dichas herramientas y su impacto en la creación de valor han sido aspectos poco analizados en estudios previos. Asimismo, la escasa investigación existente parece indicar que los hoteles no están aprovechando todo su potencial transformador. Con objeto de explorar la temática, el presente trabajo propone un marco teórico en el que se analiza cómo los hoteles pueden beneficiarse del uso de Social Media (uso de redes sociales y de sitios de revisión), examinando su impacto en resultados e introduciendo el papel mediador de las capacidades de gestión de relación con clientes usando Social Media. El trabajo supone una primera aproximación teórica al fenómeno, y constituye una base para la realización de futuros análisis empíricos.

Elastic limit: The role of university-focused venture capital firms in extending knowledge and technology transfer

This paper has two main objectives. Firstly, to identify the role of the university-focused intermediaries, specifically UVCs, in order to explain how they interact at the early stage of USO creation, particularly regarding knowledge sharing. Secondly, to analyse whether they change their position once the USO is developed. This gives rise to two Research Questions: How does knowledge sharing occur in the dynamics of a university-based entrepreneurial ecosystem? And Do particular participants, such as UTTOs or UVCs, always occupy the same role and position within the university-based entrepreneurial ecosystem?

Maintenance or loss of dialect Andalusian features: Internal and external factors

In the last sixty years a steadily maintained process of convergence towards the Castilian national standard has been occurring in Southern Spain affecting urban middle-class speakers’ varieties, particularly phonology and lexis. As a consequence, unmarked features characterising innovative southern pronunciation have become less frequent and, at the same time, certain standard marked features have been adapted to the southern phonemic inventory. Then, urban middle-class varieties have progressively been stretching out the distance separating them from working-class and rural varieties, and bringing them closer to central Castilian varieties. Intermediate, yet incipient koineised varieties have been described including also transitional Murcia and Extremadura dialects (Hernández & Villena 2009, Villena, Vida & von Essen 2015). (1) Some of the standard phonologically marked features have spread out among southern speakers exclusively based on their mainstream social prestige and producing not only changes in obstruent phoneme inventory –i.e. acquisition of /s/ vs. /θ/ contrast, but also standstill and even reversion of old consonant push- or pull-chain shifts –e.g. /h/ or /d/ fortition, affricate /ʧ/, etc. as well as traditional lexis shift (Villena et al. 2016). Internal (grammar and word frequency) and external (stratification, network and style) factors constraining those features follow similar patterns in the Andalusian speech communities analysed so far (Granada, Malaga) but when we zoom in on central varieties, which are closer to the national standard and then more conservative, differences in frequency increase and conflict sites emerge. (2) Unmarked ‘natural’ phonological features characterising southern dialects, particularly deletion of syllable-final consonant, do not keep pace with this trend of convergence towards the standard. Thus a combination of southern innovative syllable-final and standard conservative onset-consonant features coexist. (3). The main idea is that this intermediate variety is formed through changes suggesting that Andalusian speakers look for the best way of accepting marked prestige features without altering coherence within their inventory. Either reorganisation of the innovative phonemic system in such a way that it may include Castilian and standard /s/ vs. /θ/ contrast or re-syllabification of aspirated /s/ before dental stop are excellent examples of how and why linguistic features are able to integrate intermediate varieties between the dialect-standard continuum.

Synthesis and proton conduction properties of lanthanide amino-sulfophosphonates

Crystalline acid-functionalized metal phosphonates are potential candidates as proton conducting electrolytes. Their frameworks can be chemically modified to contain proton carriers such as acidic groups (P-OH; -SO3H, -COOH,…) and guest molecules (H2O, NH3,…) that generates hydrogen bond networks stable in a wide range of temperature [1,2]. In this work, focus is laid on properties derived from the combination of lanthanide ions with the amino-sulfophosphonate ligand (H2O3PCH2)2-N-(CH2)2-SO3H. Hightrough-put screening was followed to reach the optimal synthesis conditions under solvothermal conditions at 140 ºC. Isolated polycrystalline solids, Ln[(O3PCH2)2-NH-(CH2)2-SO3H].2H2O (Ln= La, Pr and Sm), crystallize in the monoclinic (La) and orthorhombic (Pr and Sm) systems with unit cell volume of ~2548 Å3. Preliminary proton conductivity measurements for Sm derivative have been carried out between 25º and 80 ºC at relative humidity (RH) values of 70 % and 95 %. The sample exhibits enhanced conductivity at high RH and T (Figure 1) and constant activation energies of 0.4 eV, typical of a Grothuss mechanism of proton.

Structure-properties correlations in divalent metal phosphonates

Crystalline metal phosphonates may offer acidic sites, structural flexibility and guest molecules (H2O, heterocyclics, etc.) which can act as proton carriers. In addition, some frameworks are also amenable for post‐synthesis modifications in order to enhance desired properties [1,2]. In this work, we present the synthesis and structural characterization of two hydroxyphosphonoacetates hybrids based on magnesium, [Mg5(O3PCHOHCOO)2(HO3PCHOHCOO)2·8H2O] [Mg5(HPAA)2(H1HPAA)2·8H2O], and zinc, [Zn6K(O3PCHOHCOO)4(OH)·6.5H2O] [Zn6K(HPAA)4(OH)·6.5H2O]. Both solids present three-dimensional frameworks and their crystal structures were solved ab initio from X-ray powder diffraction. The proton conductivity of [Zn6K(HPAA)4(OH)·6.5H2O] as well as ammonia derivatives of M(II)(HO3PCHOHCOO)·2H2O [M(II)=Zn, Mg] will be reported and discussed.

Proton conductivity and luminiscence properties of lanthanide aminotriphosphonates

Metal phosphonates are multifunctional solids with tunable properties, such as internal H-bond networks, and high chemical and thermal stability [1]. In the present work, we describe the synthesis, structural characterization, luminescent properties and proton conduction performance of a new family of isostructural cationic compounds with general formula [Ln(H4NMP)(H2O)2]Cl·2H2O [Ln = La3+, Pr3+, Sm3+, Gd3+, Tb3+, Dy3+, Ho3+, H6NMP = nitrilotris(methylphosphonic acid)]. These solids are formed by positively charge layers, which consist of isolated LnO8 polyhedra and bridge chelating NMP2- ligands, held apart by chloride ions and water molecules. This arrangement result in extended interlayer hydrogen networks with possible proton transfer pathways. The proton conductivity of Gd3+ sample, selected as prototype of the series, was measured. In the range between range 25º and 80 ºC, the conductivity increase with the temperature up to a maximum value of 3.10-4 S·cm-1, at relative humidity of 95 %. The activation energy obtained from the Arrhenius plot (Figure 1) is in the range corresponding to a Grotthuss transfer mechanism.

A bacterial acetyltransferase targets the protein kinase ZIP1, a positive regulator of plant immunity

Pseudomonas syringae is a model bacterial pathogen that penetrates the leaf to reach the plant apoplast, where it replicates causing disease. In order to do that, the pathogen must interfere and suppress a two-tiered plant defense response: PTI (PAMP-Triggered Immunity, or basal resistance) and ETI (Effector-Triggered Immunity). P. syringae uses a type III secretion system to directly deliver effector proteins inside the plant cell cytosol, many of which are known to suppress PTI, some of which are known to trigger ETI, and a handful of which are known to suppress ETI. Bacterial infection can also trigger a systemic plant defense response that protects the plant against additional pathogen attacks known as SAR (Systemic Acquired Resistance). We are particularly interested in the molecular and cellular mechanisms involved in effector-mediated defense evasion by P. syringae, in particular those involved in the suppression of ETI and SAR, and/or mediation of hormone signaling. Here we present data describing effector-mediated interference with plant immunity, by means of acetylation of a key positive regulator of local and systemic responses. Our work identifies a novel plant target for effector function, and characterizes its function. This work illustrates how analyzing the means by which a given effector interferes with its target can provide novel information regarding eukaryotic molecular mechanisms.

PAMP-triggered immunity against Pseudomonas syringae involves microRNA-mediated regulation of several uncharacterized R genes

Two main types of noncoding small RNA molecules have been found in plants: microRNAs (miRNAs) and small interfering RNAs (siRNAs). They differ in their biogenesis and mode of action, but share similar sizes (20-24 nt). Their precursors are processed by Dicer-Like RNase III (dcl) proteins present in Arabidopsis thaliana, and in their mature form can act as negative regulators of gene expression, being involved in a vast array of plant processes, including plant development, genomic integrity or response to stress. Small-RNA mediated regulation can occurs at transcriptional level (TGS) or at post-transcriptional level (PTGS). In recent years, the role of gene silencing in the regulation of expression of genes related to plant defence responses against bacterial pathogens is becoming clearer. Comparisons carried out in our lab between the expression profiles of different mutants affected in gene silencing, and plants challenged with Pseudomonas syringae pathovar tomato DC3000, led us to identify a set of uncharacterized R genes, belonging to the TIR-NBS-LRR gene family, differentially expressed in these conditions. Through the use of bioinformatics tools, we found a miRNA* of 22 nt putatively responsible for down-regulating expression of these R genes through the generation of siRNAs. We have also found that the corresponding pri-miRNA is down-regulated after PAMP-perception in a SA-dependent manner. We also demonstrate that plants with altered levels of miRNA* (knockdown lines or overexpression lines) exhibit altered PTI-associated phenotypes, suggesting a role for this miRNA* in this defence response against bacteria. In addition we identify one of the target genes as a negative regulator of defence response against Pseudomonas syringae.

kpath: An example of metabolic pathway data integration using Linked Data

The main databases related to metabolic pathways, such as Kegg, Brenda, Reactome and Biocyc, provide partially interlinked data on metabolic pathways. This limitation only allows independent searches to retrieve cross-database information on metabolism and restricts the use of more complex searches to discover new knowledge or relationships.

Bioqueries: a collaborative environment to create, explore and share SPARQL queries in Life Sciences

Bioqueries provides a collaborative environment to create, explore, execute, clone and share SPARQL queries (including Federated Queries). Federated SPARQL queries can retrieve information from more than one data source.

Algunos rasgos del modelo penal de la seguridad ciudadana: el uso intensivo del sistema penal sobre las clases desfavorecidas

Hipótesis El trabajo de investigación que se presenta parte de la hipótesis de que el modelo penal de la seguridad ciudadana está desplazando al modelo penal garantista en el sistema penal español. Objetivos y metodología Para confirmar dicha hipótesis se ha elaborado un instrumento de medida formado por diez rasgos que caracterizan al modelo penal de ley y orden. Posteriormente se ha utilizado dicho instrumento para identificar en cada fase del sistema penal ejemplos (normas y prácticas) de los diez rasgos. En concreto, se ha realizado un análisis detenido del discurso público sobre la delincuencia, las decisiones de política criminal adoptadas, los procesos legislativos desarrollados, las rutinas policiales, las prácticas judiciales y la realidad penitenciaria. Principales resultados Se han detectado multitud de dinámicas, procesos y prácticas que denotan que el modelo de la seguridad ciudadana se está implantando en el sistema penal español, aunque con diferente intensidad en cada fase, siendo más claro en el momento legislativo y estando menos presente en el de ejecución penitenciaria. Se concluye, por tanto, que el instrumento diseñado es idóneo para medir el grado de penetración del modelo a lo largo del sistema. Concretamente, se presentarán algunos de los resultados más llamativos, haciendo especial hincapié en aquellos relacionados con el uso del sistema penal para controlar de manera más intensa a las clases marginales, desatendiendo a las causas socioeconómicas de la delincuencia. En ese sentido, se pondrán de manifiesto, entre otras, las diferencias cuantitativas que resultan de la comparación entre las sanciones previstas, impuestas y ejecutadas en delitos habitualmente cometidos por clases desfavorecidas y privilegiadas. También se presentarán otros datos procedentes del análisis de las rutinas de los operadores de cada fase del sistema respecto a unos y otros delitos.